Instructions

For the Vanilla Bean Sour Cream Cupcakes:

1. Preheat the oven to 375 degrees F. Place the racks in the center position. Line cupcake tins with cupcake liners. Set aside.
2. In a large bowl combine both flours, baking powder, baking soda, and salt. Whisk to combine.
3. In a medium bowl whisk together the milk, sour cream, and egg whites. Set aside.
4. Fit a stand mixer with a paddle attachment, or use a hand mixer (I got a better dome with the hand mixer). Add the butter, sugar, and vanilla to the bowl and beat at medium speed for 3 minutes, or until light. Scrape the sides as necessary.
5. Add the vanilla extract and one third of the flour mixture while beating on medium speed, again scraping the sides as needed. Beat in half of the sour cream mixture. Alternately add the remaining flour mixture and sour cream until all the wet and dry ingredients have added, beating until the batter fully incorporated and smooth.
6. Use a large scoop (about 3 tablespoons), evenly divide the batter between 18 lined muffin tins filling each about 2/3 of the way full.
7. Bake for 15-24 minutes, or until a toothpick inserted into the centers come out clean. Cool on wire rack.

For the Vanilla Bean Buttercream:

1. In the bowl of a stand mixer fitted with the whisk attachment, combine the butter and vanilla bean seeds. Beat until fluffy. Turn the mixer to low speed and slowly add the confectioners' sugar while continuing to beat.
2. Once well blended, add in the vanilla and 4 tablespoons heavy cream or milk. Mix on low speed until well combined and moist. If desired, an additional 1 to 2 tablespoons of heavy cream or milk until your desired consistency is reached. Beat at high speed until frosting is smooth and fluffy.
3. Pipe or decorate as desired. See Two Tone Frosting for Cupcakes and Cupcake Piping Tricks for piping tips.